Records of post-smolt Atlantic salmon, Salmo salar L., in the Faroe-Shetland Channel
By R. G. J. Shelton, W. R. Turrell, A. Macdonald, I. S. McLaren, N. T. Nicoll
Fisheries Research, Volume 31, Issues 1-2, July 1997, Pages 159-162, ISSN 0165-7836, DOI: 10.1016/S0165-7836(97)00014-3.
Atlantic salmon spawn and undergo their early development in fresh water but typically make most of their growth in the sea. In the British Isles the freshwater phase may last from 1 year to, exceptionally, 5 years. The young salmon enter the sea in the spring. Because their numbers are restricted by the extent of suitable rearing habitat in fresh water, salmon are relatively uncommon fishes in the sea and records of their occurrence, other than at sites of directed fisheries have, until recently, been infrequent. Here we report on the capture of 167 post-smolt salmon caught in five trawl hauls during June 1996 in the surface waters of the Faroe-Shetland Channel. A combination of age-structure (based on scale readings) and tag-return data suggests a relatively southern origin for most of the fish. The large numbers of fish caught in two hauls and the results of analysing the tag returns suggest that post-smolt salmon form schools in the open sea. All tagged fish were of hatchery origin, suggesting that hatchery-reared fish have ocean migrations similar to wild fish, at least for part of their life at sea. Hydrographic observations obtained before and during the trawls suggest that the fish were concentrated within a persistent, narrow northward flowing slope current located along the northwest European continental shelf edge.
Keywords: Salmo salar; Post-smolt salmon migration